JP4428118B2 - PRESSURE PUMP DEVICE, LIQUID JET DEVICE, AND METHOD OF STOPPING PRESSURE PUMP - Google Patents

Description

  The present invention relates to a pressurizing pump apparatus, a liquid ejecting apparatus, and a pressurizing pump driving stop method that discharges pressurized fluid by repeating suction and discharge.

  Conventionally, a wide variety of printing devices have been developed. For example, in office and business models, a large amount of ink is consumed due to the high frequency of printing, so it is necessary to install a large capacity ink cartridge. is there. However, in a model (on-carriage type) in which an ink cartridge is placed on a carriage, if a large-capacity ink cartridge is simply placed, the carriage and thus the printing apparatus become large, and a large load is applied to the carriage itself. Therefore, an off-carriage type printing apparatus in which the carriage and the ink cartridge are separated has been developed.

  In the off-carriage type printing apparatus, it is necessary to send the ink in the ink cartridge to the carriage side (sub tank on the carriage). For this reason, a pressure pump is mounted on the printing apparatus, and the ink pack in the cartridge is crushed by sending the pressurized air from the pressure pump to the space in the ink cartridge, thereby pushing the ink to the carriage side. Then, the ink is supplied by repeating the exhaust from which the pressurization pump sends out the pressurized air and the intake air that takes in the atmosphere into the pressurization pump after the exhaust.

  As this pressurizing pump, for example, a diaphragm pump shown in Patent Document 1 is known. As shown in the same document, the printing apparatus includes a pressure detector that detects the pressure of the pressurized air discharged from the pressure pump, and a control device that calculates the pressure value of the pressurized air based on the detected value of the pressure detector. Is installed. When the pressure value of the pressurized air is lower than the set pressure, the pressurization pump is driven, and when the pressure value of the pressurized air is equal to or higher than the set value, the pressurization pump is stopped and the pressurization pump is driven.・ Pressurized air is maintained at a pressure value within a predetermined range by repeating the stop.

By the way, when the pressure waveform 90 of the pressurized air is shown in FIG. 19, the pressurized air is a period of time after the pump driving is stopped due to a minute leak in the air path or an increase in the space volume in the ink cartridge due to ink consumption. The pressure drops as it goes through. For this reason, if the pump drive is stopped immediately when the pressure value of the pressurized air reaches the set pressure, it is necessary to restart the pump drive at a short time interval, so the frequency of stopping and restarting the pump drive increases. It will interfere with pump durability. Therefore, as shown by the alternate long and short dash line in FIG. 19, even if the pressure value is equal to or higher than the set pressure, the pump drive is continued for a predetermined time and additional pressure is applied, and the pressure value of the pressurized air is set higher than the set value. This is dealt with by stopping the pump drive.
Japanese Unexamined Patent Publication No. 2000-352379 (pages 4, 5 and 1)

  Here, in some cases, when the diaphragm is contracted, the pressure value of the pressurized air becomes a set value or more, and the pressurization pump may stop when the diaphragm is contracted. In this case, the diaphragm is left in a contracted state for a long time, which may cause creep deformation of the diaphragm. When creep deformation occurs in the diaphragm, the pressurizing pump is in a state where a sufficient pressurizing force cannot be obtained, which causes a problem that the pumping performance of the pressurizing pump is deteriorated.

  An object of the present invention is to provide a pressurizing pump apparatus, a liquid ejecting apparatus, and a method for stopping driving of a pressurizing pump that can suppress deterioration in pump performance while ensuring pump durability.

  In order to solve the above problems, in the present invention, the volume of the pump chamber is increased or decreased by the reciprocating linear motion of the drive motor that is a pump drive source and the pressing member that presses the pump chamber, and the pump chamber is A pump unit that discharges pressurized fluid, a conversion mechanism that converts rotational motion of the drive motor into reciprocating linear motion of the pressing member when the drive motor rotates in at least one direction, and the pressurized fluid flows A pressurizing pump device provided with a valve mechanism that is installed in the middle of the fluid flow path pipe and opens when the drive motor rotates in the other direction, and can release the pressurization by the pressurizing fluid. Pressure detecting means for detecting the pressure of the pressurized fluid flowing through the fluid flow channel pipe, and position detecting means for detecting whether or not the pressing member is at a home position that is a movement start position of the pressing member; The pressure detection A calculation means for calculating the pressure value of the pressurized fluid based on the detected value of the stage, and a predetermined time when it is determined that the pressurization operation of the pump unit should be stopped based on the pressure value calculated by the calculation means. And a control means for starting position determination of the pressing member based on a detection value from the position detecting means after the elapse of time and stopping the drive motor when the pressing member reaches the home position. To do.

  According to this configuration, when the pressurizing operation is started, the pressurized fluid is discharged from the pump unit, and when the pressure value of the pressurized fluid reaches a value at which the pressurizing operation should be stopped, the drive motor is stopped. The pressurizing pump device operates. At this time, the position determination of the pressing member is started after a predetermined time has elapsed since it was determined that the pressing operation should be stopped. When the pressing member reaches the home position, the driving motor stops and the pressing operation stops. Therefore, after it is determined that the pressurizing operation should be stopped, a predetermined time is waited until the position of the pressing member is detected, so that the pressurizing operation is continued during this time. The pressure is increased to a pressure higher than usual.

  Here, for example, when the pressurization pump device operates so that the pressurization fluid is supplied at a pressure value within a predetermined range by repeating the pressurization operation and the pressurization release, pressurization is performed if additional pressurization is performed. Since the pressure of the fluid is higher than usual, even if a minute leak in the fluid flow pipe occurs, it is not necessary to repeat the pressurization operation and release of pressure frequently, improving the durability of the pressurization pump device and simplifying the control. Can be realized. Also, when stopping the pressurizing operation, the drive motor is stopped when the pressing member reaches the home position, so that it becomes difficult to fall into a situation where the pressing member is left for a long time at a position that causes deterioration in the pump part, A decrease in pump performance is also suppressed.

  In the present invention, the driving of the pump unit is started by rotating the driving motor in one direction, and when the pressure value becomes equal to or higher than a set pressure, the driving of the pump unit is stopped, and when the pressure value falls below the set pressure The pump unit includes a pressurization operation control unit that performs a pressurization operation by re-driving and repeating this operation, and the control unit performs the pressurization operation by the pressurization operation control unit, and the pressure value is After the predetermined time has elapsed since the pressure became equal to or higher than the set pressure, the position determination of the pressing member based on the detection value from the position detection means is started, and the drive motor is stopped when the pressing member reaches the home position Then, the gist is to stop the driving of the pump unit.

  According to this configuration, even if the pressurization operation and the release of pressurization are repeated so that the pressurized fluid is supplied at a pressure value within a predetermined range, the pressurized fluid is pressurized to a pressure higher than normal by additional pressure. Therefore, it is not necessary to repeat the pressurizing operation and the pressurization release frequently. Therefore, if the pressurization operation and release of pressure are repeated frequently, an excessive load is applied to the pressurization pump device, which may affect the life of the device, etc., but by adopting the configuration of this example, the pressurization pump device The durability can be improved and the control can be simplified.

  In the present invention, when it is determined that pressure release should be performed based on the detected value of the pressure detecting means or the operation to the apparatus main body, the valve mechanism is opened by rotating the drive motor in the other direction. Pressure release control means for releasing pressure, and when the pressure release is executed by the pressure release control means, after the pressure value falls below a predetermined threshold, the control means The gist of the invention is to start position determination of the pressing member based on the detected value, and stop the drive motor when the pressing member reaches the home position.

  According to this configuration, since the pressure release is performed when abnormal pressurization or when the apparatus power is turned off, there is a high possibility that the pressure pump apparatus will be in a dormant state for a long time after the pressure release. However, when the motor driving is stopped when the pressure is released, the driving motor is stopped when the pressing member reaches the home position, so that the driving of the pressure pump device is stopped in a state where the pressing member is positioned at a suitable position. Therefore, it is not necessary to leave the pressing member at an unfavorable position for a long period of time, which is very effective in suppressing the pump performance deterioration.

  In the present invention, when the pressure release is executed by the pressure release control means, the control means detects the detected value from the position detection means after the predetermined time has elapsed after the pressure value falls below the predetermined threshold. The position determination of the pressing member based on is started, and the driving motor is stopped when the pressing member reaches the home position.

  According to this configuration, even if the pressure value falls below the threshold value, the valve opening operation is continued for a predetermined time. Therefore, the operation time for opening the valve mechanism can be extended, and the pressure release can be more reliably performed. It becomes possible.

The gist of the present invention is that the predetermined time is a time required for the pressing member to reciprocate at least once.
According to this configuration, for example, when the pressurized fluid is pressurized to a higher pressure than usual by additional pressure during the pressurizing operation, at least the pressing member makes one or more reciprocations, so that the pressurized fluid can be increased to a sufficient pressure value. It becomes possible.

  In the present invention, a liquid cartridge that discharges liquid by expanding and contracting an internal liquid container by supplying pressurized fluid to the internal space, a liquid ejecting head that can eject the liquid, and a liquid in the liquid cartridge A liquid channel tube for guiding the pressurized fluid to the space of the liquid cartridge, a pressure pump device for supplying pressurized fluid to the space of the liquid cartridge, and a fluid channel tube for guiding the pressurized fluid to the space of the liquid cartridge; The pressurizing pump device includes a drive motor that serves as a pump drive source and a pressing member that presses the pump chamber in a reciprocating linear motion, whereby the volume of the pump chamber increases and decreases. A pump unit that discharges pressurized fluid from the chamber and a change that converts the rotational motion of the drive motor into a reciprocating linear motion of the pressing member when the drive motor rotates in at least one direction. And a valve mechanism that is installed in the middle of the fluid flow path pipe through which the pressurized fluid flows, and that is opened when the drive motor rotates in the other direction and can release the pressurization by the pressurized fluid Pressure detecting means for detecting the pressure of the pressurized fluid flowing through the fluid flow channel pipe, and position detecting means for detecting whether or not the pressing member is at a home position that is a movement start position of the pressing member; A predetermined time when it is determined that the drive motor should be stopped based on the pressure value calculated by the calculation means and the pressure value calculated by the calculation means based on the detection value of the pressure detection means And a control means for starting position determination of the pressing member based on a detection value from the position detecting means after the elapse of time and stopping the drive motor when the pressing member reaches the home position. Do

  According to this configuration, when the pressurizing operation is started, the liquid cartridge is supplied with the pressurized fluid from the pump unit, and when the pressure value of the pressurized fluid reaches a value at which the pressurizing operation should be stopped, the driving is performed. The pressurizing pump device operates to stop the motor. At this time, the position determination of the pressing member is started after a predetermined time has elapsed since it was determined that the pressing operation should be stopped. When the pressing member reaches the home position, the driving motor stops and the pressing operation stops. Therefore, after it is determined that the pressurizing operation should be stopped, a predetermined time is waited until the position of the pressing member is detected, so that the pressurizing operation is continued during this time. The pressure is increased to a pressure higher than usual.

  Here, for example, when the pressurization pump device operates so that the pressurization fluid is supplied at a pressure value within a predetermined range by repeating the pressurization operation and the pressurization release, pressurization is performed if additional pressurization is performed. Since the pressure of the fluid is higher than usual, even if a minute leak of the fluid flow pipe occurs, it is not necessary to repeat the pressurizing operation and release of pressure frequently, and the durability of the pressurizing pump device and thus the liquid ejecting device is improved. And simplification of control. Also, when stopping the pressurizing operation, the drive motor is stopped when the pressing member reaches the home position, so that it becomes difficult to fall into a situation where the pressing member is left for a long time at a position that causes deterioration in the pump part, A decrease in pump performance is also suppressed, and the reliability of the liquid ejecting apparatus is improved.

  In the present invention, a pump motor that serves as a pump drive source, and a pump unit that discharges pressurized fluid from the pump chamber by increasing or decreasing the volume of the pump chamber by a reciprocating linear movement of a pressing member that presses the pump chamber. And a conversion mechanism that converts the rotational motion of the drive motor into a reciprocating linear motion of the pressing member when the drive motor rotates in at least one direction, and a fluid flow path pipe through which the pressurized fluid flows. A pressure pump device comprising: a valve mechanism that can be opened when the drive motor rotates in the other direction and can release the pressurization by the pressurized fluid; and a control unit that controls the drive motor The pressurization pump drive stop control method used in the above is a method for detecting the pressure of the pressurized fluid flowing through the fluid flow channel pipe by the pressure detection means, and pressing the pressure member to the home position which is the movement start position of the pressing member. Whether or not there is a material is detected by the position detection means, and the pressure value of the pressurized fluid is calculated by the calculation means based on the detection value of the pressure detection means, and the control means is calculated by the calculation means When it is determined that the drive motor should be stopped based on the pressure value, after a predetermined time has elapsed, the position determination of the pressing member based on the detection value from the position detection means is started, and the pressing member is moved to the home position. The gist is to stop the drive motor when reaching. According to the present invention, an effect similar to that of the first aspect can be obtained.

Hereinafter, an embodiment of a pressurizing pump device, a liquid ejecting apparatus, and a pressurizing pump driving stop method embodying the present invention will be described with reference to FIGS.
FIG. 1 is a plan view illustrating a schematic configuration in a case of the printing apparatus 1. The printing apparatus 1 is an off-carriage type in which a carriage 3 and an ink cartridge 4 are provided inside a main body case 2 and the carriage 3 and the ink cartridge 4 are separated. The carriage 3 is attached to an endless timing belt 7 stretched by a driving pulley 5 and a driven pulley 6, and this timing belt 7 is driven by a carriage motor 8 so that it is guided by a guide shaft 9. It reciprocates in the scanning direction (left and right direction in FIG. 1). The printing apparatus 1 corresponds to a liquid ejecting apparatus, and the ink cartridge 4 corresponds to a liquid cartridge.

  A recording head 10 having a plurality of nozzle holes is attached to the lower surface of the carriage 3. On the lower end side of the printing apparatus 1, a paper feed motor (see FIG. 13) is mounted as a drive source for feeding print paper. A gear is fixed to the output shaft of the paper feed motor 11, and this gear is connected to the paper feed roller 12 and the paper discharge roller 13 (both are shown in FIG. 13) via a gear train. When the paper feed motor 11 rotates, the paper feed roller 12 and the paper discharge roller 13 rotate, and the paper 14 is fed along the paper feed member 15 in the sub-scanning direction (vertical direction in FIG. 1). The recording head 10 corresponds to a liquid ejecting head.

  A sub tank (also referred to as a valve unit) 16 that supplies ink to the recording head 10 is mounted on the carriage 3. The ink cartridges 4 and the sub tanks 16 are provided in the number of ink colors (for example, black, yellow, magenta, and cyan), and the sub tanks 16 are connected to the ink cartridges 4 of the respective colors through the ink supply tubes 17 for the respective colors. Each sub tank 16 temporarily stores the ink taken from the ink cartridge 4, adjusts the stored ink to a predetermined pressure, and supplies the ink to the recording head 10.

  A pressure unit 18 is mounted on the upper surface of the ink cartridge 4 at the end of the main body case 2. The pressurizing unit 18 is a device that sends out pressurized air (pressurized fluid) to the ink cartridge 4 via the air supply tube 19, and includes a pressurizing pump 20, a pressure sensor 21, and an atmosphere release valve 22. The air supply tube 19 is branched into a plurality (four in this example) by a distributor 23 on the downstream side of the atmosphere release valve 22, and each branched tube is connected to each color of the ink cartridge 4. The ink supply tube 17 corresponds to a liquid channel tube, the pressure unit 18 corresponds to a pressure pump device, the air supply tube 19 corresponds to a liquid channel tube, and the pressure sensor 21 corresponds to a pressure detection means.

  The ink cartridge 4 is detachably accommodated in a cartridge holder 24 included in the main body case 2. As shown in FIG. 2, the ink cartridge 4 includes an ink pack 25 in which ink is sealed, and an ink case 26 that houses the ink pack 25. The ink pack 25 has an ink discharge port 25a, and the ink supply tube 17 is connected to the ink discharge port 25a. Only the ink discharge port 25 a of the ink pack 25 is exposed to the outside, and the other portions are stored in the ink case 26 in an airtight state, whereby an airtight space 27 is formed inside the ink case 26. The ink pack 25 corresponds to the liquid storage unit.

  The ink case 26 has a communication hole (not shown) that communicates with the space 27, and the air supply tube 19 is connected to the communication hole so that the communication hole and the air supply tube 19 are electrically connected. It has become. When the pressurizing pump 20 is operated and the pressurized air is discharged, the pressurized air is introduced into the space 27 in the ink cartridge 4 through the air supply tube 19, and the ink pack 25 is moved by the air pressure of the pressurized air. It is crushed. As a result, the ink in the ink pack 25 is supplied to the sub tank 16 via the ink supply tube 17.

  In this way, the pressure of the pressurized air rises as the exhaust and intake of the pressurizing pump 20 are repeated, the ink pack 25 is crushed, and the ink is supplied to the sub tank 16. The ink is temporarily stored in the sub tank 16 and supplied to the recording head 10 in a state where the pressure is adjusted. The printing apparatus 1 drives a carriage motor 8 and a paper feed motor 11 based on print data fetched from a host computer or a memory card, and ejects ink from the recording head 10 to execute a printing process.

  FIG. 3 is a perspective view of the pressure unit 18, and FIG. 4 is a plan view of the pressure unit 18. The pressurizing pump 20 is a diaphragm pump, and includes a pump motor 28 as a pump driving source and a pump unit 30 having a pump chamber 29 (see FIGS. 7 and 8) inside. The pressurizing unit 18 is unitized by attaching a pressurizing pump 20, a pressure sensor 21 and an air release valve 22 to a metal mounting plate 31. Therefore, the pressurization unit 18 is assembled to the main body case 2 by attaching the mounting plate 31 to the main body case 2 with a plurality of screws or the like. The rotation of the pump motor 28 is converted into a reciprocating linear motion via the gear mechanism 32 and the cam mechanism 33 and transmitted to the pump unit 30.

  The gear mechanism 32 and the cam mechanism 33 will be described below. As the pump motor 28, for example, a small DC motor is used, and a motor gear 34 is fixed to the output shaft thereof. On the other hand, a wall portion 31a erected perpendicularly to the bottom wall of the mounting plate 31 is bent at the end edge of the mounting plate 31, and the first support shaft 35 faces the pump motor 28 on the wall portion 31a. It is integrally formed to extend. The first support shaft 35 has a large diameter at the base and a small diameter at the tip side, and a first gear 36 is supported on the small diameter portion of the first support shaft 35 in a rotatable state. The first gear 36 includes a large diameter gear 36 a and a small diameter gear 36 b, and the large diameter gear 36 a is engaged with the motor gear 34. The pump motor 28 corresponds to a drive motor, and the gear mechanism 32 and the cam mechanism 33 constitute a conversion mechanism.

  The pump unit 30 includes a diaphragm (bellows) 37 whose one end is opened in a circular shape, and a lid unit 38 that closes the opening 37a (see FIGS. 7 and 8) of the diaphragm 37 in a sealed state. Accordingly, the inside of the diaphragm 37 closed by the lid portion 38 functions as the pump chamber 29. The diaphragm 37 has a bellows shape with a plurality of side walls folded back, and is manufactured by blow molding a resin or the like. The diaphragm 37 can be expanded and contracted in the longitudinal direction (in the direction of arrow A shown in FIG. 4) using the pump motor 28 as a drive source, and the volume of the pump chamber 29 increases and decreases with this expansion and contraction operation.

  A plurality (three in this example) of claw portions 38 a are formed on the end surface of the lid portion 38. On the other hand, a holding wall 31 b erected perpendicularly to the bottom wall of the mounting plate 31 is formed on the mounting plate 31 at a position facing the end surface of the lid portion 38. A circular locking hole 31c is formed in the central portion of the holding wall 31b. The pump portion 30 is fixed to the mounting plate 31 on the base end side (that is, the lid portion 38 side) by locking the claw portion 38 a in the locking hole 31 c. The other end of the diaphragm 37 is attached with a pressing member 39 that reciprocates linearly based on the rotational movement of the pump motor 28 to expand and contract the diaphragm 37.

  FIG. 5 is a perspective view of the pressing member 39 and parts related thereto, and FIG. 6 is a perspective view of FIG. 5 viewed from the opposite side. The pressing member 39 includes a flat base 40 and a columnar piston 41 integrally formed with the base 40. On the back surface of the base 40, an engagement piece 40a extending in a direction approaching each other is formed. The engaging piece 40a is formed in a portion excluding the side surface 40c of the base portion 40 so that the accommodation groove 40b formed inside the engaging piece 40a is open at the side surface 40c of the base portion 40.

  On the other hand, an engaging portion 37b (see FIGS. 7 and 8) is formed at the end of the diaphragm 37 in a shape matching the housing groove 40b. The engaging portion 37b protrudes from the end portion (end surface) of the diaphragm 37, and the outer side has a larger diameter than the inner side so that the engaging portion 37b can be locked in the receiving groove 40b of the pressing member 39. It is formed in a shape. Therefore, the diaphragm 37 is assembled to the pressing member 39 by fitting the engaging portion 37 b into the receiving groove 40 b from the side surface 40 c of the base portion 40.

  As shown in FIG. 3 and FIG. 4, a pair of support pieces 31 d and 31 d are bent on the mounting plate 31 at a position facing the piston 41. These support pieces 31d and 31d extend perpendicularly to the bottom wall of the mounting plate 31, and support holes 31e and 31e (see FIG. 4) are formed at the same height in each of the support pieces 31d and 31d. The piston 41 of the pump unit 30 is inserted into the pair of support holes 31e and 31e so as to be capable of reciprocating linear movement, whereby the piston 41 is supported by the mounting plate 31.

  As shown in FIGS. 3 and 4, a second gear 42 that can be rotated together with the first gear 36 is disposed between the pair of support pieces 31 d and 31 d. As shown in FIGS. 5 and 6, the second gear 42 includes a large-diameter portion tooth portion 42a and a small-diameter portion cylindrical portion 42b. The second gear 42 is formed with a communication hole 42c that communicates with both the tooth portion 42a and the cylindrical portion 42b. The tooth part 42a and the cylindrical part 42b are located on the same axis. The second gear 42 is supported so as to be rotatable relative to the piston 41 by inserting the piston 41 into the communication hole 42c. The gear mechanism 32 includes a motor gear 34, a first gear 36, and a second gear 42.

  A cam groove 43 is formed on the outer peripheral surface of the piston 41 in such a shape that the rotational motion of the pump motor 28 can be converted into the reciprocating linear motion of the piston 41. On the other hand, a circular hole 42d is formed on the side wall of the cylindrical portion 42b, and a pair of latching portions 42e and 42e are formed on the outer peripheral surface of the cylindrical portion 42b with the hole 42d interposed therebetween. A connecting piece 44 that can be locked in the cam groove 43 of the piston 41 is attached to the hole portion 42d in a state of being positioned by a substantially U-shaped metal fixing piece 45. The cam mechanism 33 includes a pressing member 39, a cam groove 43, a connecting piece 44, and a fixed piece 45.

  An engaging portion 44 a that can be engaged with the cam groove 43 is formed on the back surface of the connecting piece 44, and a protrusion 44 b is formed on the surface of the connecting piece 44. The pair of side walls of the fixed piece 45 are formed with retaining holes 45a and 45a capable of retaining the retaining portions 42e and 42e, and the bottom wall connecting the side walls is a recess 45b (which can latch the protrusion 44b). 6) is formed. When the connecting piece 44 is positioned in the hole portion 42d of the cylindrical portion 42b, its own protruding portion 44b fits into the concave portion 45b of the fixed piece 45, and a pair of engaging portions 42e are inserted into the engaging holes 45a of the fixed piece 45. By being in the latched state, it is held in the positioned state.

  The connecting piece 44 is positioned and fixed by a fixing piece 45 in a state where its locking portion 44 a is locked in the cam groove 43. By the way, when the pump motor 28 is rotated, the first gear 36 and the second gear 42 are rotated along with it, and when the second gear 42 is rotated, the connecting piece 44 is rotated together therewith. At this time, the rotational motion of the pump motor 28 is converted into the reciprocating linear motion of the piston 41 due to the shape of the cam groove 43 that the locking portion 44a of the connecting piece 44 locks. Due to the reciprocating linear motion, the diaphragm 37 expands (state of the solid line in FIG. 4) or contracts (state of the one-dot chain line in FIG. 4).

  7 and 8 are side sectional views of the pump unit 30. FIG. The lid portion 38 of the pump unit 30 is formed with an intake port 38 b that serves as an inlet for the atmospheric air into the pump chamber 29 and an exhaust port 38 c that serves as a discharge port for pressurized air in the pump chamber 29. An intake one-way valve 46 allowing only air flow into the pump chamber 29 is connected to the intake port 38b, and an exhaust one-way valve 47 allowing only air flow outside the pump chamber 29 to the exhaust port 38c. Is connected. Therefore, the pressurizing amount of the pump unit 30 increases every time the diaphragm 37 is expanded and contracted by this check valve structure.

  When the piston 41 linearly moves (forward movement) toward the diaphragm 37 (in the direction of arrow B shown in FIG. 7) as the pump motor 28 rotates, the diaphragm 37 contracts from the state shown in FIG. 7 to the state shown in FIG. At this time, the diaphragm 37 is in an exhaust state, and the pressurized air in the pump chamber 29 is supplied to the ink cartridge 4 from the exhaust port 38c. On the other hand, when the piston 41 linearly moves (returns) in the direction opposite to the diaphragm (in the direction of arrow C shown in FIG. 7) as the pump motor 28 rotates, the diaphragm 37 extends from the state shown in FIG. 8 to the state shown in FIG. . At this time, the pump chamber 29 is in an intake state, and air in the atmosphere is sent into the pump chamber 29 from the intake port 38b.

  As shown in FIGS. 3 and 4, the pressure sensor 21 is a sensor capable of detecting the pressure of the pressurized air discharged from the pump unit 30 and outputting a detection value corresponding to the pressure. The pressure sensor 21 includes an input connection pipe 21a that serves as an inlet for pressurized air and an output connection pipe 21b that serves as an outlet for the taken-in pressurized air. In the pressure sensor 21, the input connection pipe 21a is connected to the exhaust connection pipe 30a of the pump unit 30 via the first air supply tube 19a, and the output connection pipe 21b is connected to the atmosphere release valve 22 via the second air supply tube 19b. It is connected to the suction connection pipe 22a.

  FIG. 9 is a plan view showing an exploded state of the friction clutch mechanism. A friction clutch mechanism 48 is disposed between the first gear 36 and the atmosphere release valve 22. This will be described below. The second support shaft 49 is fixed to the wall portion 31 a of the mounting plate 31. The second support shaft 49 has a large diameter at the base and a small diameter at the tip side, and a third gear 50 is rotatably attached to a small diameter portion of the second support shaft 49. A fixing pin 51b is fixed to the tip of the second support shaft 49 through a washer 51a, and the third gear 50 is held by the fixing pin 51b so as not to fall out of the second support shaft 49. The atmosphere release valve 22 and the friction clutch mechanism 48 constitute a valve mechanism.

  The third gear 50 meshes with the small diameter gear 36 b of the first gear 36. A driven component 52 is attached between the third gear 50 and the wall 31a. The driven component 52 can be rotated together with the third gear 50 by the friction clutch mechanism 48. The driven component 52 has a through hole 52a at the center, and the through hole 52a is inserted into the large diameter portion of the second support shaft 49 so as to be rotatably supported by the second support shaft 49. Yes. On the side surface of the driven component 52, a pushing portion 52b that protrudes to the side larger than the outer diameter of the driven component is formed. The protruding length of the pushing portion 52b is set to a length that reaches the atmosphere release valve 22.

  A spring spring (hereinafter referred to as a first spring) 53 that urges the driven component 52 toward the third gear 50 is interposed between the driven component 52 and the wall portion 31a. One end of the first spring 53 is in contact with the side surface of the wall portion 31 a and the other end is in contact with the inner wall 52 c of the driven component 52. The third gear 50 and the driven component 52 are in contact with each other with a pressing force corresponding to the biasing force of the first spring 53, and the wall surface of the third gear 50 that contacts the driven component 52 functions as the clutch surface 50a. Further, the reduction ratio by the friction clutch between the third gear 50 and the driven component 52 is set larger than the reduction ratio between the first gear 36 and the second gear 42.

  When the pump motor 28 is rotated, the third gear 50 is rotated via the first gear 36, and the friction clutch mechanism 48 is operated in accordance with the rotation operation, so that the driven component 52 is rotated in the same direction as the third gear 50. . Incidentally, since the pump motor 28 can rotate forward and backward, in this example, when the pump motor 28 rotates forward, the driven component 52 moves to the opposite side of the atmosphere release valve 22 (that is, in the direction of arrow D shown in FIG. 3). When the pump motor 28 is reversely rotated, it is rotated toward the atmosphere release valve 22 (that is, in the direction of arrow E shown in FIG. 3). The friction clutch mechanism 48 includes a third gear 50, a driven component 52, and a first spring 53.

  10 to 12 are cross-sectional views showing the operating state of the atmosphere release valve 22. The atmosphere release valve 22 is a valve having two functions of an atmosphere release function and a regulator function, and includes a valve body 54 having a passage of pressurized air and a valve release lever 55 for opening and closing the atmosphere release valve 22. I have. The valve body 54 includes a suction port 54a that serves as an inlet for pressurized air sent from the pressure pump 20 via the pressure sensor 21, a valve chamber 54b that functions as a pressure detection chamber for pressurized air in the valve, And an outlet 54c serving as an outlet for the pressurized air.

  The valve body 54 is formed with a valve hole 56 that communicates the valve chamber 54 b with the outside (atmosphere), and a valve seat 57 is formed at the outlet periphery of the valve hole 56. A rotary shaft 58 extending along the axial direction of the second support shaft 49 is installed on the valve main body 54, and the valve release lever 55 is swingably supported by the rotary shaft 58. A valve (valve) 59 capable of opening and closing the valve hole 56 is formed on the surface of the valve opening lever 55 on the valve hole 56 side so as to project.

  On the other hand, between the upper wall of the valve body 54 and the valve opening lever 55, a spring spring (hereinafter referred to as a second spring) 60 for biasing the tip of the valve opening lever 55 toward the valve hole 56 is interposed. ing. Spring receivers 54 d and 55 a for engaging the second spring 60 are formed on the lower surface of the upper wall of the valve main body 54 and the surface opposite to the valve hole 56 at the tip of the valve opening lever 55. A third air supply tube 19 c extending from the distributor 23 is connected to the discharge connection pipe 22 b of the atmosphere release valve 22.

  In a normal state (that is, when the pump motor 28 is rotating forward), the valve opening lever 55 is biased by the second spring 60 as shown in FIG. Since 59 closes the valve hole 56, the air release valve 22 is closed. At this time, the driven component 52 rotates in the direction of arrow D in FIG. 10 due to the forward rotation of the pump motor 28. However, even if the pump motor 28 continues to rotate in the forward direction, the driven component 52 moves to the first support shaft 35 after a while. The contact is restricted and the rotation is restricted, and no further rotation occurs.

  The operation of the pressurizing pump 20 is switched between the stopped state and the driving state based on the pressure value P obtained from the detection value of the pressure sensor 21. That is, when the pressure value P becomes equal to or higher than the set pressure Pa after the pump drive is started, the pressurizing pump 20 is stopped and temporarily stops the pump drive. Start and resume pump drive. By repeating this process, the pressurized air supplied to the ink cartridge 4 is maintained at a pressure value within a predetermined range.

  On the other hand, when the pressure value P rises excessively and becomes equal to or higher than the threshold value Pb (> Pa), the air release function of the air release valve 22 is activated. At this time, first, the pump motor 28 starts reverse rotation instead of forward rotation, and accordingly, the driven component 52 starts rotating in the direction of arrow E in FIG. When the driven component 52 rotates for a while in the direction of arrow E, the pushing portion 52b of the driven component 52 comes into contact with the proximal end of the valve opening lever 55 as shown in FIG. 11, and the lever proximal end is pushed downward. Then, the valve opening lever 55 swings against the urging force of the second spring 60, the lever tip is lifted upward, the valve 59 is separated from the valve hole 56, and the atmosphere opening valve 22 is opened.

  The air release valve 22 also has a regulator function. This is because the pressurized air in the air supply tube 19 does not become excessive pressure even if the control system of the pressure sensor 21 or the printing apparatus 1 fails (runaway). It is for doing so. This will be described below. The threshold value Pc (> Pb) for operating the regulator function is set based on the spring force (biasing force) of the second spring 60. Accordingly, when the pressure value P of the pressurized air is equal to or higher than the threshold value Pc, the lever tip is lifted upward by the air pressure in the valve chamber 54b as shown in FIG.

  Further, the atmosphere release function of the atmosphere release valve 22 is activated even when the power of the printing apparatus 1 is turned off. This is because, if the air supply tube 19 remains in a pressurized state when the printing apparatus 1 is turned off, it is difficult to remove the ink cartridge 4 or ink leaks from the gap of the ink discharge port 25a. This is because the problem arises. Therefore, when the power of the printing apparatus 1 is turned off, the state where the power is supplied to the power supply circuit using a delay circuit or the like is maintained for a predetermined time, and the pump motor 28 is reversed during that time to release the air release valve 22. Open the valve.

  As shown in FIG. 4, a home detector 61 for detecting the expansion / contraction position X of the diaphragm 37 is attached to the mounting plate 31 in the vicinity of the pressing member 39. The home detector 61 is a detector that detects whether or not the diaphragm 37 is in a fully extended state (that is, positioned at the home position (home position) X0), and the position of the pressing member 39 is observed. Thus, it is detected whether or not the diaphragm 37 is positioned at the home position X0.

  For example, a limit switch or an optical sensor is used as the home detector 61. The home detector 61 includes a detection lever 61 a that can rotate with respect to the detector main body, and the detection lever 61 a is disposed on the movement path of the base 40. When the diaphragm 37 is positioned at the home position X0, the home detector 61 is in a state where the base 40 pushes the detection lever 61a, and is turned on to output a detection signal. The home detector 61 corresponds to position detection means.

  FIG. 13 is a block diagram illustrating an electrical configuration of the printing apparatus 1. The printing apparatus 1 includes a CPU 62, a ROM 63, a RAM 64, an I / F 65, and an ASIC 66, and these devices are electrically connected through a bus 67. The CPU 62 manages the main control of the printing apparatus 1 and operates using the RAM 64 as a work area based on a control program stored in the ROM 63. The printing apparatus 1 is connected to the host computer 68 via the I / F 65 and performs printing processing based on print data transmitted from the host computer 68. The CPU 62 and the ASIC 66 constitute calculation means, control means, pressurization operation control means, and pressurization release control means.

  The ASIC 66 operates based on a command from the CPU 62, and the carriage motor 8 through the first motor drive circuit 69, the paper feed motor 11 through the second motor drive circuit 70, and the recording head 10 through the head drive circuit 71. Is controlled. The ASIC 66 is electrically connected to the pressure sensor 21 and calculates the pressure value P of the pressurized air based on the detection value from the pressure sensor 21. Then, the ASIC 66 controls the drive of the pump motor 28 via the third motor drive circuit 72 based on the calculated pressure value P. Further, the ASIC 66 is electrically connected to the home detector 61. When a detection signal is input from the home detector 61, it is determined that the diaphragm 37 is at the home position X0.

  Next, when the printing apparatus 1 starts the printing apparatus, the pressurizing operation by the pressurizing pump 20 is executed by the ASIC 66. This pressurizing operation will be described with reference to the flowchart shown in FIG.

  In step 100, it is determined whether or not the pressure value P of the pressurized air has become equal to or higher than the set pressure Pa (pressure value P ≧ set pressure Pa is established). That is, the pressure value P of the pressurized air is calculated based on the detection value from the pressure sensor 21, and it is determined whether or not the pressure value P is equal to or higher than the set pressure Pa. If the pressure value P is not equal to or higher than the set pressure Pa, it is determined that the pressurizing operation should be performed, and the process proceeds to step 101. If the pressure value P is equal to or higher than the set pressure Pa, it is determined that the pressurizing operation is unnecessary. This flowchart is finished.

  In step 101, the pump motor 28 is rotated forward. Accordingly, the forward rotation of the pump motor 28 is transmitted to the cam mechanism 33 through the gear mechanism 32, and the rotation of the pump motor 28 is converted into the reciprocating linear motion of the pressing member 39 by the cam mechanism 33. Then, when the diaphragm 37 expands and contracts, the pressurized air is discharged from the pump chamber 29, and the pressure value P of the pressurized air gradually increases as the diaphragm 37 repeats the expanding and contracting operation.

  In step 102, it is determined whether or not the pressure value P of the pressurized air is equal to or higher than a set pressure Pa. Here, if the pressure value P is equal to or higher than the set pressure Pa, it is determined that the pressurizing operation has been normally performed, and the routine proceeds to step 103. On the other hand, if the pressure value P does not exceed the set pressure Pa, the routine proceeds to step 107.

  In step 103, the system stands by for a predetermined time Tk. That is, it waits for the predetermined time Tk before moving to the next operation. The predetermined time Tk is a value longer than the time required for the pressing member 39 to reciprocate at least once. For example, if it takes about 1 second to make one reciprocation of the pressing member 39, the predetermined time Tk is set to a value of 1 second or longer.

In step 104, home detection is started to determine whether or not the diaphragm 37 is located at the home position X0.
In step 105, it is determined whether or not a detection signal is input from the home detector 61. Here, if a detection signal is input from the home detector 61, it is determined that the diaphragm 37 is located at the home position X0, and the routine proceeds to step 106. On the other hand, if the detection signal is not input from the home detector 61, the routine proceeds to step 108.

  In step 106, the pump motor 28 during normal rotation is stopped. Therefore, the pressurizing pump 20 stops the expansion / contraction operation when the diaphragm 37 is located at the home position X0, that is, when the diaphragm is fully extended. Thereafter, this flowchart is re-executed and the compressed air is maintained at a pressure value within a predetermined range by repeatedly executing the flowchart.

  When it is determined in step 102 that the pressure value P is not equal to or higher than the set pressure Pa, in step 107, the elapsed time Tx after the forward rotation of the motor has passed the set time Ty (elapsed time Tx> set time Ty is established. Or not). Here, if the elapsed time Tx has not passed the set time Ty, it is determined that pressurization is still in progress and the process returns to S102.

  On the other hand, if the elapsed time Tx has passed the set time Ty, it is determined that an abnormality has occurred somewhere in the apparatus, and a fatal error is notified. Examples of the device abnormality include a case where the pump motor 28 does not rotate and a hole is formed in the diaphragm 37. Since the printing apparatus 1 is equipped with a display screen (LCD, monitor), display lamp (LED), and buzzer (including a speaker, etc.), at least one of the display screen, the display lamp, and the buzzer causes a fatal error. Notification is performed.

  When it is determined in step 105 that no detection signal is input from the home detector 61, in step 108, the elapsed time Tb from the start of detection of the detection signal has passed the set time Tn (elapsed time Tb). > Set time Tn is established). If the elapsed time Tb has not passed the set time Tn, the process returns to step 105 to continue detecting the detection signal. If the elapsed time Tb has passed the set time Tn, it is determined that an abnormality has occurred in the apparatus. To report a fatal error.

  By the way, depending on the operating state of the printing apparatus 1, there may be a case where the pressurized air in the air supply tube 19 is excessively increased in pressure. The cause of the excessive increase in pressure includes, for example, an increase in the temperature of the printing apparatus 1 due to long-time use. The ASIC 66 determines that the pressurized air is excessively increased when the calculated pressure value P of the pressurized air is equal to or greater than the threshold value Pb. Accordingly, the ASIC 66 performs a pressure release operation, that is, an operation of opening the atmosphere release valve 22 in order to reduce the pressure in the air supply tube 19.

  Next, the pressure release operation performed by the ASIC 66 will be described with reference to the flowchart shown in FIG. The ASIC 66 executes this flowchart with a trigger that the pressure value P of the pressurized air exceeds the threshold value Pb.

In step 200, the pump motor 28 is reversed. Therefore, the driven component 52 starts to rotate in the direction of arrow E in FIG.
In step 201, it is determined whether or not the elapsed time Ta after the motor reverse rotation has passed the set time Tm (elapsed time Ta> set time Tm is established). Here, if the driven component 52 rotates as normal, the pushing portion 52b of the driven component 52 tilts the valve release lever 55 as shown in FIG. 11, and the atmosphere release valve 22 is opened. Therefore, the pressurized air in the air supply tube 19 is released to the outside, and the overpressurized state is eliminated. If elapsed time Ta> set time Tm is satisfied, the routine proceeds to step 202, and if elapsed time Ta> set time Tm is not satisfied, the process waits as it is.

In step 202, the pump motor 28 in reverse rotation is stopped.
In step 203, it is determined whether or not the pressure value P of the pressurized air is equal to or greater than a threshold value Pb (pressure value P ≧ threshold value Pb is established). Here, if the pressure value P of the pressurized air is below the threshold value Pb, the atmosphere is released normally by the atmosphere release valve 22, and the routine proceeds to step 204. On the other hand, if the state where the pressure value of the pressurized air remains equal to or higher than the threshold value Pb continues, the atmosphere release by the atmosphere release valve 22 is not normally performed, and the process proceeds to step 207.

  In step 204, the reverse rotation of the pump motor 28 is resumed. Here, since the reciprocating linear motion of the piston 41 is performed even when the pump motor 28 is reversely rotated, the diaphragm 37 is positioned at the home position X0 by restarting the reverse rotation of the pump motor 28. When the reverse rotation of the pump motor 28 is resumed, the pushing portion 52b remains in contact with the valve opening lever 55, but the rotation of the pump motor 28 is allowed because the friction clutch functions.

  In step 205, it is determined whether or not a detection signal is input from the home detector 61. Here, if a detection signal is input from the home detector 61, it is determined that the diaphragm 37 is positioned at the home position X0, and the process proceeds to step 206. If no detection signal is input from the home detector 61, the diaphragm 37 is still at the home position. It is determined that the position is not at position X0, and the routine proceeds to step 110.

  In step 206, the pump motor 28 is stopped. Therefore, the expansion / contraction operation of the pressurizing pump 20 stops when the diaphragm 37 is located at the home position X0, that is, when the diaphragm is fully extended.

  On the other hand, when it is determined in step 203 that the pressure value P ≧ threshold value Pb is established, in step 207, the pump motor 28 is rotated forward. Accordingly, the driven component 52 starts to rotate in the direction of arrow D shown in FIG. 10, and the pushing portion 52 b of the driven component 52 is returned to a position away from the valve release lever 55.

In step 208, the pump motor 28 during normal rotation is stopped.
In step 209, it is determined whether or not a retry has been performed a set number of times. By the way, when the pressure value P does not decrease even when the pump motor 28 is reversed, the operation of rotating the pump motor 28 once and rotating it again (that is, releasing the atmosphere by the reverse rotation of the pump motor 28) is retried. Retry is set in advance so that it can be executed a predetermined number of times (set number of times). For example, if the set number of times is set to 3, whether or not the total number of retries has reached 3 times is determined. To be judged.

  If the total number of retries has not reached the set number, the process returns to step 200 to retry the air release by the reverse rotation of the pump motor 28, and if the total number of retries has reached the set number, the apparatus has an abnormality. Is determined and a fatal error is notified.

  On the other hand, when it is determined in step 205 that the detection signal is not input from the home detector 61, in step 210, the elapsed time Tb from the start of input detection of the detection signal has passed the set time Tn (elapsed time Tb). > Set time Tn is established). If the elapsed time Tb has not passed the set time Tn, the process returns to step 205 to continue detection of the detection signal. If the elapsed time Tb has passed the set time Tn, a fatal error is notified.

  Here, for example, it is assumed that the value of the predetermined time Tk is set to a time necessary for the pressing member 39 to reciprocate once. In this case, if the pressure waveform 73 of the pressurized air is shown in FIG. 16, even if the pressure value P reaches the set pressure Pa, the pump motor 28 is stopped after the diaphragm 37 is extended and contracted once more. Become. When additional pressure is applied in this way, the pressure value P does not immediately fall below the set pressure Pa even if there is a small leak in the air supply tube 19 or a pressure drop due to an increase in the volume of the space 27 due to ink consumption. . Therefore, it is not necessary to frequently repeat the pressurizing operation and the pressurizing release, thereby improving the durability of the pump and simplifying the pressurization control.

  Further, when the pressure value P becomes equal to or higher than the set pressure Pa, the pressurization pump 20 stops. However, after the additional pressurization, the pump motor 28 is stopped when the diaphragm 37 is positioned at the home position X0. The pressurizing pump 20 stops. Here, when the diaphragm 37 is left in a contracted state for a long time, the diaphragm 37 undergoes creep deformation, which hinders the pressurizing force of the pressurizing pump 20. However, since the pressure pump 20 is stopped when the diaphragm 37 is located at the home position X0, the problem of creep deformation does not occur, and the pump performance is ensured over a long period of time.

Therefore, according to this embodiment, the following effects can be obtained.
(1) Even if the pressure value P of the pressurized air becomes equal to or higher than the set pressure Pa, the pressurizing operation is continued for a predetermined time Tk and the additional pressure is applied. Therefore, a pressure drop occurs due to air leakage or ink consumption. However, the pressurizing operation is not immediately resumed. Accordingly, it is not necessary to frequently repeat the pressurizing operation / pressurization release, and it is possible to improve the durability of the pump and simplify the pressurization control. Further, the position detection of the diaphragm 37 is started after the additional pressurization, and the pump motor 28 is stopped when the diaphragm 37 is positioned at the home position X0. Deformation is unlikely to occur, and pump performance can be ensured over a long period of time.

  (2) When releasing the pressure at the time of excessive pressure at all times or when the power of the printing apparatus 1 is turned off, when the release of the pressure is finished, the diaphragm 37 stops with the diaphragm 37 fully extended based on the detection result of the home detector 61. Accordingly, since the diaphragm 37 is stopped in the fully extended state even when the pressure is released, the diaphragm 37 is unlikely to undergo creep deformation or the like, and the pressure pump 20 is unlikely to deteriorate in pressure.

  (3) The predetermined time Tk is set to a value longer than the time required for the pressing member 39 to reciprocate at least once. Therefore, when additional pressure is applied, the pressurized air can be increased to a sufficient pressure value.

  (4) When the pressure value P of the pressurized air does not increase even if the pump drive is started during the pressurizing operation, or when the pressure does not decrease even when the air release valve 22 is opened when releasing the pressure, When the diaphragm 37 is not positioned at the home position X0 at the end of the pressurizing operation and the operation at the time of releasing the pressurization, a fatal error is notified visually or by sound. Accordingly, it is possible to notify the user that an abnormality has occurred in the printing apparatus 1.

  (5) Since the pressurization operation and the pressurization release of the pressurization pump 20 are performed by switching the rotation direction of the same motor, it is not necessary to use an electromagnetic valve or the like for opening and closing the atmosphere release valve 22. The pressurizing unit 18 and thus the printing apparatus 1 can be reduced in size. Further, when opening the atmosphere release valve 22, simple control of reversing the pump motor 28 is sufficient, and therefore, the opening control of the atmosphere release valve 22 becomes simple.

  (6) The pressure value P of the pressurized air is sequentially calculated based on the detection value from the pressure sensor 21, and when the pressure value P becomes equal to or greater than the threshold value Pb, the pump motor 28 reverses and the atmosphere release valve 22 is opened. Controlled. Accordingly, the pressurized air does not increase excessively, and the air supply tube 19 and the ink supply tube 17 are not easily damaged, and the durability of the pressure unit 18 and the printing apparatus 1 is improved. Can do.

  (7) The intake one-way valve 46 is provided at the intake port 38 b of the pump unit 30, and the exhaust one-way valve 47 is provided at the exhaust port 38 c of the pump unit 30. Therefore, the diaphragm 37 has a configuration in which the applied pressure of the diaphragm 37 increases as the diaphragm 37 expands and contracts. Therefore, a sufficient applied pressure can be obtained even if the diaphragm 37 is downsized. Contributes to further downsizing.

  (8) When the pressure value P of the pressurized air staying in the valve chamber 54b of the atmosphere release valve 22 is equal to or greater than the threshold value Pc (> Pb), the valve release lever 55 swings against the urging force of the second spring 60. And the atmosphere release valve 22 is automatically opened. Therefore, for example, even if the pressure sensor 21 fails or the control system of the CPU 62 fails, the air release valve 22 is automatically opened. The reliability of the device 1 is improved.

  (9) Since a friction clutch is used as a mechanism for transmitting the rotation of the pump motor 28 to the driven component 52, the pump 52 is brought into contact with the valve release lever 55 when the air release valve 22 is opened. There is no problem even if the motor 28 continues to rotate. Therefore, the control of the pump motor 28 is simplified, and a position detector for viewing the rotational position of the pump motor 28 is not required.

  (10) When a friction clutch is used as a mechanism for transmitting the rotation of the pump motor 28 to the driven component 52, the driven component 52 rotates with the pressurizing operation of the pressurizing pump 20 based on the normal rotation of the pump motor 28. However, since the reduction ratio by the friction clutch between the third gear 50 and the driven component 52 is set larger than the reduction ratio between the first gear 36 and the second gear 42, the load necessary for the pressurizing operation is set. That is, the load other than the load necessary for operating the pump unit 30 can be reduced.

  (11) Even when the power of the printing apparatus 1 is turned off, the pump motor 28 is reversed to open the atmosphere release valve 22, so that the air supply tube 19 is turned on when the printing apparatus 1 is not turned on. Or the ink cartridge 4 is not filled with pressurized air. Therefore, when the printer 1 is not turned on, the air supply tube 19 and the ink cartridge 4 can be set to atmospheric pressure, and problems such as ink leakage can be made difficult to occur.

The embodiment is not limited to the above-described configuration, and may be changed to the following modes.
(Modification 1) The diaphragm 37 is not limited to the bellows shape, and may be a saddle shape as shown in FIGS. 17 (a) and 17 (b), for example.

  (Modification 2) The pump unit 30 is not limited to the structure using the diaphragm 37. For example, as shown in FIGS. 18A and 18B, a cylinder 81 may be used. In this structure, a piston 82 is accommodated in a cylinder 81 so as to be able to reciprocate, and an O-ring 83 is interposed between the piston 82 and the cylinder inner wall. Then, when the piston 82 reciprocates, the volume of the pump chamber 29 increases and decreases, and the pressurized air is discharged. Also in this case, if the one-way valve 46 for intake and the one-way valve 47 for exhaust are connected to the cylinder 81, sufficient pressurization characteristics can be obtained even if the cylinder itself is small. The pressure unit 18 and thus the printing apparatus 1 can be reduced in size.

  (Modification 3) The process of detecting the home position after a predetermined time Tk has elapsed after the pressure sensor 21 detects the predetermined pressure is not limited to the pressurizing operation, and may be performed when the pressure is released. That is, using the flowchart shown in FIG. 15, after the pressure value P falls below the threshold value Pb in step 203, the process waits for a predetermined time Tk, and when the predetermined time Tk elapses, the pump motor 204 is reversed in step 204. You may make it resume. In this case, the valve opening operation can take a long time, so that the pressure can be released more reliably.

  (Modification 4) The pressure detection means is not limited to the pressure sensor 21 that outputs a signal corresponding to the detected pressure value, but may be an on / off type sensor that outputs an on signal when a predetermined pressure value is reached.

  (Modification 5) The position detection means is not limited to the home detector 61 that outputs an ON signal when the diaphragm 37 is positioned at the home position X0, but a sensor that can output a signal having a level corresponding to the expansion / contraction state of the diaphragm 37. But you can.

(Modification 6) The value of the predetermined time Tk is not particularly limited as long as the value is equal to or longer than the time required for the pressing member 39 to reciprocate at least once.
(Modification 7) The pump motor 28 is not limited to a DC motor, and an AC motor may be used.

  (Modification 8) The mechanism for transmitting the rotation of the pump motor 28 to the cam mechanism 33 and the friction clutch mechanism 48 is not limited to the gear mechanism 32. For example, the rotation of the pump motor 28 to the cam mechanism 33 and the friction clutch mechanism 48 by a timing belt is used. May be communicated.

(Modification 9) The cam mechanism 33 is not limited to the cylindrical cam of the embodiment, and various methods such as a heart cam, a front cam, and an end cam may be employed.
(Modification 10) The mechanism for transmitting the rotation of the pump motor 28 to the driven component 52 is not limited to the friction clutch mechanism 48, and the structure is such that the air release valve 22 is opened when the pump motor 28 reverses. If there is no particular limitation. Further, when a clutch mechanism is used for this mechanism, the clutch mechanism is not limited to a friction clutch, and a meshing clutch or the like may be employed.

(Modification 11) The fluid supplied from the pressurizing pump 20 to the ink cartridge 4 is not limited to air, and liquid or the like may be used.
(Modification 12) The liquid ejecting apparatus is not limited to the printing apparatus 1. For example, the liquid ejecting apparatus is a color filter manufacturing apparatus such as a liquid crystal display, an electrode forming apparatus such as an organic EL display or FED (surface emitting display), an ejecting apparatus that ejects bioorganic matter for biochip manufacturing, and a manufacturing apparatus for precision pipettes. Etc. The printing apparatus 1 may employ various jockeys such as an ink jet type and a thermal transfer type.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(1) In claim 1 or 2, when the pressure value is equal to or higher than a first threshold value that is an excessive pressure value, the valve mechanism is opened by rotating the drive motor in the other direction. A pressure release control unit that performs pressure release, and the control unit performs the predetermined time after the pressure value falls below a value lower than the first threshold when the pressure release is executed by the pressure release control unit. After the elapse of time, the position determination of the pressing member based on the detection value from the position detecting means is started, and when the pressing member reaches the home position, the drive motor is stopped.

  (2) In any one of claims 1 to 5, the pump unit includes a check valve (46) that allows only intake of fluid from the outside in an intake port (38b), and only exhausts the pressurized fluid. This is constituted by a diaphragm (37) in which a check valve (47) that permits the above is arranged in the exhaust port (38c).

  (3) In any one of Claims 1-5, the said pump part distribute | arranged the check valve which accept | permits only the intake of the fluid from the outside to an inlet, and the check valve which accept | permits only the exhaust of the said pressurized fluid Is constituted by a cylinder (81) arranged at the exhaust port.

  (4) In any one of claims 1 to 5, the valve mechanism includes a lever member (55) supported so as to be swingable with respect to the valve body (54), and a valve (59 formed integrally with the lever member). ), A valve hole (56) opened and closed by the valve, and a biasing member (60) for biasing the lever member in the valve closing direction, and when the drive motor is rotating in one direction, The lever member is urged toward the valve hole by the urging force of the urging member, the valve is closed, and when the precursor drive motor rotates in the other direction, the valve mechanism is actuated to swing the lever member. Then, the valve is opened.

  (5) In any one of claims 1 to 5, the valve mechanism has a second threshold value in which the pressure value of the pressurized fluid staying in its valve chamber (54b) is set to a value larger than the first threshold value. If it becomes above, the said valve will be in an open state automatically.

  (6) The valve mechanism according to any one of claims 1 to 5, wherein when the drive motor rotates in the other direction, the driven component (52) rotates with the drive motor via a friction clutch. A friction clutch mechanism for swinging the lever member by abutting the pushing portion (52b) of the component against the lever member is provided.

  (7) In the technical idea (6), the reduction ratio of the friction clutch is set larger than the reduction ratio of the gear mechanism (36, 42) that transmits the rotation of the drive motor to the conversion mechanism.

FIG. 2 is a plan view illustrating a schematic configuration in a case of the printing apparatus according to the embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of an ink cartridge. FIG. 3 is a perspective view of a pressure unit that sends pressurized air to an ink cartridge. FIG. 3 is a plan view of a pressure unit that sends pressurized air to an ink cartridge. The perspective view of a transmission member and parts related to it. FIG. 6 is a perspective view when FIG. 5 is viewed from the opposite side. Side cross-sectional view of the pump when in the intake state The sectional side view of a pump part at the time of an exhaust state. The top view which shows the decomposition | disassembly state of a clutch mechanism. Sectional drawing of the air release valve at the time of a valve closing state. Sectional drawing of the air release valve at the time of a valve opening state. Sectional drawing of an air release valve when it will be in a valve opening state itself. FIG. 2 is a block diagram illustrating an electrical configuration of the printing apparatus. The flowchart which ASIC performs at the time of pressurization operation | movement. The flowchart which ASIC performs at the time of pressure release. The wave form diagram which shows the time change of the pressure value of pressurized air, and the time change of the output value of a home detector. It is a sectional side view of the pump part in another example, (a) is a sectional side view of the pump part in the intake state, (b) is a sectional side view of the pump part in the exhaust state. It is a sectional side view of the pump part in other examples, (a) is a sectional side view of the pump part in the intake state, (b) is a sectional side view of the pump part in the exhaust state. The wave form diagram which shows the time change of the pressure value of the pressurized air in the past.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printing apparatus as liquid ejecting apparatus, 2 ... Main body case as apparatus main body, 4 ... Ink cartridge as liquid cartridge, 10 ... Recording head as liquid ejecting head, 17 ... Ink supply tube as liquid channel pipe, DESCRIPTION OF SYMBOLS 18 ... Pressurization unit as a pressurization pump apparatus, 19 ... Air supply tube as a fluid flow path pipe, 20 ... Pressurization pump, 21 ... Pressure sensor as a pressure detection means, 22 ... Air release valve which comprises a valve mechanism 25 ... an ink pack as a liquid storage unit, 27 ... a space, 28 ... a pump motor as a drive motor, 29 ... a pump chamber, 30 ... a pump unit, 32 ... a gear mechanism constituting a conversion mechanism, 33 ... a conversion mechanism Cam mechanism, 37 ... diaphragm, 39 ... pressing member, 48 ... friction clutch mechanism constituting a valve mechanism, 61 ... ho as position detecting means Detector, 62... Calculation means, control means, CPU constituting pressure operation control means and pressure release control means, 66... ASIC constituting calculation means, control means, pressure action control means and pressure release control means 81, cylinder, Tk, predetermined time, P, pressure value, Pa, set pressure, Pb, threshold.

Claims (7)

A pump motor that serves as a pump drive source, a pump unit that increases and decreases the volume of the pump chamber as a pressing member that presses the pump chamber linearly reciprocates, and discharges pressurized fluid from the pump chamber, and the drive motor Is installed in the middle of the fluid flow channel pipe through which the pressurized fluid flows, and a conversion mechanism that converts the rotational motion of the drive motor into a reciprocating linear motion of the pressing member when the motor rotates in at least one direction. A pressure pump device comprising a valve mechanism that is open when the valve rotates in the other direction and is capable of releasing pressurization by the pressurized fluid,
Pressure detecting means for detecting the pressure of the pressurized fluid flowing through the fluid flow path pipe;
Position detecting means for detecting whether or not the pressing member is at a home position which is a movement start position of the pressing member;
Calculation means for calculating a pressure value of the pressurized fluid based on a detection value of the pressure detection means;
When it is determined that the pressurization operation of the pump unit should be stopped based on the pressure value calculated by the calculation means, the position determination of the pressing member based on the detection value from the position detection means after a predetermined time has elapsed. And a control means for stopping the drive motor when the pressing member reaches the home position. The drive motor is rotated in one direction to start driving the pump unit. When the pressure value is equal to or higher than a set pressure, the drive of the pump unit is stopped, and when the pressure value falls below the set pressure, the pump unit is It is provided with a pressurizing operation control means for performing a pressurizing operation by re-driving and repeating this operation,
When the pressurization operation is performed by the pressurization operation control unit, the control unit performs the pressing based on the detection value from the position detection unit after the predetermined time has elapsed since the pressure value has become equal to or higher than the set pressure. 2. The pressurizing pump device according to claim 1, wherein the position determination of the member is started, and when the pressing member reaches the home position, the driving motor is stopped and the driving of the pump unit is stopped. When it is determined that the pressure release should be released based on the detected value of the pressure detection means or the operation of the apparatus body, the valve mechanism is opened to increase the pressure by rotating the drive motor in the other direction. Provided with a pressure release control means for releasing,
The control means starts the position determination of the pressing member based on the detection value from the position detection means after the pressure value falls below a predetermined threshold at the time of pressure release execution by the pressure release control means, The pressurizing pump device according to claim 1 or 2, wherein when the pressing member reaches the home position, the drive motor is stopped.   When the pressure release is executed by the pressure release control means, the control means performs the pressing based on the detection value from the position detection means after the predetermined time has elapsed after the pressure value falls below the predetermined threshold. The pressure pump device according to any one of claims 1 to 3, wherein the position determination of the member is started and the drive motor is stopped when the pressing member reaches the home position.   The pressurizing pump device according to any one of claims 1 to 4, wherein the predetermined time is a time required for the pressing member to reciprocate at least once. When a pressurized fluid is supplied to the internal space, the internal liquid container expands and contracts to discharge the liquid, a liquid ejecting head capable of ejecting the liquid, and liquid ejecting the liquid cartridge to the liquid ejecting liquid A liquid comprising: a liquid channel pipe that leads to a head; a pressure pump device that supplies a pressurized fluid to the space of the liquid cartridge; and a fluid channel pipe that guides the pressurized fluid to the space of the liquid cartridge. In the injection device,
The pressurizing pump device is
A pump motor that serves as a pump drive source, a pump unit that increases and decreases the volume of the pump chamber as a pressing member that presses the pump chamber linearly reciprocates, and discharges pressurized fluid from the pump chamber, and the drive motor Is installed in the middle of the fluid flow channel pipe through which the pressurized fluid flows, and a conversion mechanism that converts the rotational motion of the drive motor into a reciprocating linear motion of the pressing member when the motor rotates in at least one direction. A valve mechanism that is opened when the valve rotates in the other direction and is capable of releasing the pressurization by the pressurized fluid,
Pressure detecting means for detecting the pressure of the pressurized fluid flowing through the fluid flow channel pipe, position detecting means for detecting whether or not the pressing member is at a home position which is a movement start position of the pressing member, and the pressure detection Calculating means for calculating the pressure value of the pressurized fluid based on the detected value of the means, and when it is determined that the drive motor should be stopped based on the pressure value calculated by the calculating means, after a predetermined time has elapsed, A liquid ejecting apparatus comprising: control means for starting position determination of the pressing member based on a detection value from the position detecting means, and stopping the drive motor when the pressing member reaches the home position. . A pump motor that serves as a pump drive source, a pump unit that increases and decreases the volume of the pump chamber as a pressing member that presses the pump chamber linearly reciprocates, and discharges pressurized fluid from the pump chamber, and the drive motor Is installed in the middle of the fluid flow channel pipe through which the pressurized fluid flows, and a conversion mechanism that converts the rotational motion of the drive motor into a reciprocating linear motion of the pressing member when the motor rotates in at least one direction. Is applied to a pressurizing pump device including a valve mechanism capable of releasing the pressurization by the pressurizing fluid and a control means for controlling the drive motor. A method for stopping driving of a pressure pump,
The pressure of the pressurized fluid flowing through the fluid flow channel tube is detected by pressure detection means, and the position detection means detects whether or not the pressing member is at the home position that is the movement start position of the pressing member. The pressure value of the pressurized fluid is calculated by the calculating means based on the detected value of the means,
When the control means determines that the drive motor should be stopped based on the pressure value calculated by the calculation means, the position of the pressing member based on the detection value from the position detection means after a predetermined time has elapsed. A method for stopping the driving of a pressurizing pump, wherein determination is started and the driving motor is stopped when the pressing member reaches the home position.

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